Damper



Dec. 29, 1942. c. A. OTTO DAMPER Filed Sept. 19, 1941 THEEMOSTAT Damn nllmmm TH E QM OS AT Jnventor @CuzE CLOHm DAMPER Carl A. Otto, Milwaukee. Wis., assignor to Johnson Service Company, Milwaukee, Wis., a corporation of Wisconsin Application September 19, 1941, Serial No. 411,597

2 Claims.

This invention relates to dampers for controlling the discharge of conditioned air into a room.

Where conditioned air is discharged horizontally from a duct into a room there is a tendency for the air to sink if it is cooler than the room air and a tendency to rise if it be warmer. This causes drafts, stratification and other objectionable effects.

Dampers have heretofore been developed in which the damper blades form a sort of nozzle which maintains the velocity of discharge as the damper closes. The present invention combines with such a damper and its thermostatic controlling mechanism, a set of louvers and means automatically effective to set the louvers to give upward deflection of the discharging air or downward deflection of the discharging air depending on whether such air is cooled or heated.

The most satisfactory and positive way to accomplish this is to use a convertible summerwinter thermostat to control the damper. Such a thermostat has two settings in which respectively its controlling action is reversed with respect to temperature. The deflecting louvers are operatively related to the setting mechanism so that the louvers and the setting mechanism are reversed by a single controller.

The preferred arrangement is to use a pneumatic thermostat whose reversal is effected by changin the pressure at which air is supplied to it, and control the louvers by a pressure motor which is subject to supply pressure and which shifts in response to changes therein.

The preferred embodiment of the invention will now be described by reference to the accompanying drawing, in which:

Fig. 1 is a vertical section through a duct and damper arrangement according to the invention. The parts are shown as set to deliver cooled air, that is, summer operation.

Fig. 2 is a similar view showing the parts set to deliver heated air, i. e., winter operation.

A duct 6 leads horizontally from any distributing system or duct for conditioned air, such air being cooled in summer and heated in winter by means, not shown. The duct discharges through wall 1 into room 8 and the end of the duct is con cealed by a grille 9 of any suitable type.

In the frame I I of grille 9 and behind the grille are a series of parallel louvers l2 pivoted on horizontal axes l3 and connected to shift in unison by the link M pivoted to the various louvers. These louvers are shiftable between a summer position (Fig. 1) and a winter position (Fig. 2), 55

the angle of displacement between said positions being about 90.

The louvers are shifted by a pressure motor generally indicated by numeral l5 affixed to its body. This is of th metal bellows type. The bellows l6 react on lever l1 pivoted at l8 to the body of the motor. The lever IT is connected by link I9 to arm 2| fast to the lowermost louver l2. A tension spring 22 urges the parts to winter position, this detail arising from the fact that in the example illustrated low supply pressure conditions the thermostat, hereinafter described, for winter operation.

Mounted in duct 6 is a damper frame 23 carrying across its top and bottom respectively, the axes 24 and 25 for two plane damper blades 26 and 21. A damper motor comprising a cylinder 28 with piston rod 29 is mounted in the duct. The rod 29 carries a clevis 3| pinned at 32 to two links 33 and 34 which are pinned at 35 and 36 to clips on the blades 26 and 21.

Such dampers are well known in the art and because of a nozzle effect tend to sustain the discharge velocity even as they close. The rod 29 is biased to damper-closed position by a spring within cylinder 28 but not visible in the drawing, and moves in a damper opening direction in response to rising pressure in branch line 31, the motion of rod 29 being approximately pro portional to branch line pressure.

The branch line 3'! leads from a thermostat 38 of the general type illustrated in the patent to Otto, No. 2,021,263 issued November 19, 1935, so arranged that when subject to a high supply pressure (17 pounds per sq. in.) it gives a sum mer cycle which for the structure illustrated is rising branch line pressure with rising temperature (Class 1 operation). Similarly when subject to a lower supply pressure (13 pounds per sq. in.) it gives a winter cycle which for the structure illustrated is falling branch line pressure with rising temperature (Class 2 operation).

The supply line 39 furnishing air to thermostat 38 also leads to motor l5 and spring 22 is so chosen that at 17 pounds the louvers l2 are turned to summer position (Fig. 1) while at 13 pounds the spring overpowers the bellows and shifts the louvers I 2 to winter position (Fig. 2).

A switch valve 4| selectively connects line 29 to one or the other of two sources of air supply represented by the 17 pound tank 42 for summer control and the 13 pound tank 43 for winter control.

The pressures stated are intended to be illustrative, as is the particular arrangement illustrated. Various modifications within the scope of the claims are possible and are contemplated.

I claim:

1. The combination of a duct adapted to discharge into a room; flow deflecting means associated with the discharge end of said duct and shiftable selectively between a summer position and a winter position; a gradual acting volume damper controlling flow through said duct; a damper motor for adjusting said damper; a gradual acting thermostat responsive to room temperature and connected to control said damper motor in accordance with changes of temperature, said thermostat including reversing means for establishing summer and winter conditions in which respectively its controlling action in said motor is reversed with respect to temperature; and a controller for shifting said deflecting means and actuating said reversing means.

2. The combintion of a duct adapted to discharge into a room; flow deflecting means associated with the discharge end of said duct and shiftable selectively between a summer position and a winter position; a gradual acting volume damper controlling flow through said duct; a damper motor for adjusting said damper; a gradual acting pneumatic thermostat connected to control said damper motor in accordance with changes of temperature, said thermostat including an air supply connection and means responsive to changes of supply pressure for reversing with respect to temperature the controlling ac tion of said thermostat; a pneumatic motor having a supply connection, said motor being connected to shift said deflecting means and arranged to respond to changes of supply pressure to shift said deflecting means between said two positions; and shiftable means connected to supply air to the supply connections of said thermostat and motor at two alternate pressures, sufliciently different to reverse the thermostat and shift said motor.

CARL A. O'I'IO. 

